Electric circuit controller



March 21, 1950 E. T. GRANT 2,501,507

ELECTRIC CIRCUIT CONTROLLER Filed Nov. 21, 1947 Fig 6.

2 Z Inventor: g A ll Eduard T Grant, F b3 :5 I Hus Attorney.

Patented Mar. 21, 1950 ELECTRIC CIRCUIT CONTROLLER Eduard T. Grant, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application November 21, 1947, Serial No. 787,431

7 Claims. (01. 200-166) My invention relates to electric circuit controllers and more particularly to contact spring mounting arrangement for electromagnetic re lays.

It is a general object of my invention to pro vide a new and improved electric circuit controller which is durable and reliable in operation and simple and inexpensive in manufacture and assembly.

More specifically, it is an object of my invention to provide new and improved mounting means for a movable spring contact member carrying a pair of adjacent contacts, the mounting means being arranged to exert compound flexure of the spring throughout substantially its entire length and to provide equalization of contact pressure throughout the range of wiping movement of the contacts.

It is an outstanding feature of my invention that, by reason of the geometrical configuration of the contact spring and the arrangement of the pressure points cooperating with the spring, a wide variety of contact working forces and contact pressure gradients may be readily attained without departing from the scope of the invention.

My invention itself will be more fully understood and its various objects and advantages further appreciated by referring now to the following detailed specification taken in conjunction with the accompanying drawing, in which Fig. 1 is a side view of an electromagnetic relay embodying my invention; Figs. 2 and 3 are end and plan views, respectively, of the relay shown at Fig. 1; Fig. 4 is a cross-sectional view taken along the lines 4-4 of Fig. 3; and Figs.5 and 6 are de tailed cross-sectional views of the juncture between the relay frame and center leg or coil core, illustrating the manner in which the core is joined to the frame to form a permanent and fixed gap in the magnetic circuit.

Referring now to the drawing, the circuit controlling electromagnetic relay shown therein by way of illustration. of my invention comprises a U shapedmagnetizable frame III having mounted thereon a center leg, or coil core, Illa. The core Illa is fixedly attached to the bight portion of the U-shaped frame I in the manner illustrated at Figs. 5 and 6. In fastening the core Illa to the frame III, a tenon formed at the lowei' end of the core Ilia, is fitted into a mortise in the frame with a copper ring or shim II (Fig.5) ina portion of the copper shim I I flows by capillary action into the space between the tenon and the frame III, as shown at Ila, Fig. 6. The annulus I la of copper forms a small fixed and permanent gap in the magnetic circuit as more fully described and claimed in my copending patent application Serial No. 787,432 filed November 21, 1947 for Eduard T. Grant and assigned to the same assignee as the present application.

The center leg, or core, Illa has mounted thereon an annular energizing winding or coil lb,

and is provided at its upper surface with a shading coil Illc. The shading coil is suitably formed as an inlaid ring of electric conducting material and the center portion of the core Illa within the shading coil is raised slightly above the top surface of the adjacent coil and outer annular portion of the core, as shown at Fig. 4.

The U-shaped frame II) has connected thereto, as by clamping bolts I2, a stationary contact block I3, formed of a suitable moulded insulatin material and including a central dividing Wall I3a. On opposite sides of the central wall I3a are mounted fixed contacts I4 and I5 and connected wire terminals Ma and I5a, respectively. On opposite outer sides of the contact block I3 are mounted coil terminals I6 and II. It will be understood that the coil leads (not shown) are connected to the terminals I6 and II.

In the embodiment of the invention shown, the relay is provided also with an upper stationary contact block I8 having a center dividing wall. Mounted upon the block I8 at opposite sides of the center wall IBa are two fixed contacts I9 and 20 and connected wire terminals 2| and 22, respectively. The upper contact block I8 is bolted to the lower contact block I3 by a bolt 23. It will, of course, be understood by those skilled in the art that the upper contact block I8 and the contacts I9 and 20 may be omitted if it is desired that the relay be provided only with normally open contacts.

Pivotally mounted upon one end leg, i..e., the rear leg, of the U -shaped frame I0 is an elongated magnetizable armature 24. The armature extends iorwardly towards the fixed contacts across the top of the frame In to the front leg, and extends slightly to the rear to provide a connecting hook for a biasing tension spring 25. The spring 25 is connected between the rear extension of the armature 24 and an car 26 turned out from the rear leg of the frame III to provide a connecting hook for the opposite end of the spring.

The front leg of the frame In is slightly shorter than the center portion of the core Illa, so that when the armature 24 is attracted into engagement with the core Illa, a small air gap is left between the armature and the front leg of the frame at the point 21. The magnetic circuit through the front leg of the frame is therefore provided with two gaps, at He and 21, while the magnetic circuit through the rear leg of the frame is provided with a single gap at Ila.

The pivoted armature 2i formsone part of a movable switch member carrying a pair of moving contacts for cooperation with the fixed contacts I4, l5, l5 and 20. To support the moving contacts, there is mounted upon the armature 24 a head 28 comprising a block of moulded insulating material substantially co-extensive in length with the length of the armature 24 and provided for a portion of its length with a central dividing wall 28a. The head 28 is fixed to the armature 24 by a bolt 30 and a cap 3| of moulded insulating material, and as so mounted, it has a rear end 28b furthest from the fixed contacts and a front end 280 nearest to the fixed contacts. The cap 3| is formed as a block of insulating material having a cylindrical boss 3|a. The bolt 30 passes through the cylindrical boss 3|a and through the insulating head 28 into threaded engagement with the armature 24, molding the boss 3|a seated in a cylindrical recess in the head 28 and firmly clamping both the head 28 and the cap 3| in position on the armature 24. The cylindrical boss 3| a is of such length that when the cap or insulating block 3| is clamped in position, the upper portion of the block 3| is in parallel spaced relation with respect to the lower insulating block 28.

Intcrposed between the spaced apart insulating blocks 23 and 3|, is an elongated leaf spring 32 having a generally H-shaped configuration and disposed with its transverse leg extending transversely across the armature, i. e., parallel to the pivotal axis of the armature, and intermediate the ends but adjacent the unpivoted end of the armaturc. The rcarwardly extending side legs of the leaf spring 32 are disposed on opposite sides of the dividing wall 28a of the insulating head 28, and the forwardly extending side legs or furcations of the spring 32 extend beyond the end of the armature and beyond the ends of blocks 28 and 3| nearest the fixed contacts. Each of these side legs has fixedly mounted at its free end one of the moving contacts 33, 33.

The contact leaf spring 32 is seated at the rear upon elongated bosses or abutments 35 formed at the rear end 28b of the insulating block 28 and extending substantially parallel to the pivotal axis of the armature. At the front the spring 32 is seated upon an elongated transverse boss or abutment 36 projecting upwardly from the front end 28c of the block 28. The spring 32 is clamped in position on the bosses 35 and 36 and pre-stressed to some extent by depending elongated transverse bosses or abutments 31 formed upon the upper insulating block or cap 3|. The bosses 31 engage the side less of the contact leaf spring 32 at points intermediate the supporting bosses 35 and 36, and preferably at points relatively close to the rear boss 35. To further hold the spring 32 in position on the block 28, its rear legs are apertured to fit over a pair of positioning pins 38 formed on the rear abutments 35. It is to be understood that by an elongated boss I do not necessarily mean that such boss is continuous transversely across the block, but I also intend to include by this term two or more aligned bosses which constitute, in effect. an elongated shoulder or support.

In order to equalize the pressure exerted by the two extending contact carrying legs of the leaf spring 32, the upper insulating block or head 2| is provided also with a depending point abutment or knob-like boss I. which projects downwardly from the upper block toward the midpoint of the transverse leg of the H-shaped spring. Normally, with the armature in its dropped out position and the spring resting upon the lower insulating block at the boss ll, the knob-like boss 3! is spaced from the spring. However, when the armature is attracted to the frame, to bring the normally open contacts into engagement, the spring 32 is deformed during the contact wiping portion of the armature movement and is brought into substantially point engagement with the upper boss or abutment 39. The application of pressure at this point of the spring during the wiping movement effects a compound fiexurc of the spring throughout substantially its entire length, and maintains the contact pressures substantially equal throughout the range of contact wiping movement.

While I have described only a preferred embodiment of my invention by way of illustration, many modifications will occur to those skilled in the art, and I therefore wish to have it understood that I intend in the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an electric circuit controller having a base and a fixed contact mounted on said base, a movable switch member comprising a pair of blocks of insulating material connected together in parallel spaced relation and mounted for pivotal movement about a transverse axis of one of said blocks, said One block being provided at opposite ends thereof with spaced apart elongated abutments extending parallel to the pivotal axis of said block and projecting toward the other said block, said other block being provided with an elongated abutment parallel to said pivotal axis and projecting toward said first block intermediate the abutments on said first block, an elongated flexible leaf spring held in clamping relation between said abutments and extending beyond the ends of said blocks nearest said fixed contact, a movable contact fixedly mounted upon the extending end of said spring for cooperation with said fixed contact, and means for moving said switch member between contact opening and contact closing positions, said leaf spring flexing throughout substantially its entire length in said contact closing position to elect wiping movement of said contacts.

2. In an electric circuit controller having a base and a pair of spaced apart fixed contacts mounted on said base, a movable switch member comprising a pair of blocks of insulating material connected together in parallel spaced relation and mounted for pivotal movement about a transverse axis of one of said blocks, said one block being provided at opposite ends thereof with a. pair of spaced apart elongated abutments extending parallel to the pivotal axis of said block and projecting toward the other said block. said other block being provided with an elongated abutment parallel to said pivotal axis and projecting toward said first block intermediate the abutments on said first block, an elongated flexible leaf spring held in clamping relation between said abutments and extending beyond the ends of said blocks nearest said fixed contacts a movable contact fixedly mounted upon the extending end of said spring for cooperation with said fixed contacts, and means for moving said switch member between spaced apart positions of engagement of said spring mounted contact with one or the other of said fixed contacts, said blocks engaging said springat the ends of said blocks nearest said fixed contacts in each contact engaging position to effect fiexure of said spring throughout its length and wiping movement of said contacts.

3. In an electric circuit controller having a base and a fixed contact mounted on said base, a movable switch member comprising a pair of blocks of insulating material connected together in parallel spaced relation and mounted for pivotal movement about a transverse axis adjacent one end of one of said blocks, said one block being provided at opposite ends thereof with spaced apart elongated abutments extending parallel to the pivotal axis of said block and projecting toward the other said block, said other block being provided with an elongated abutment parallel to said pivotal axis and projecting toward said first block intermediate the abutments on,

said first block, an elongated flexible leaf spring held in clamping relation between said abutments and extending beyond the unpivoted end of said blocks, a movable contact fixedly mounted upon the extending end of said spring for cooperation with said fixed contact, means for biasing said switch member to a position to maintain said contacts separated, and means for moving said switch member against its bias to engage said contacts and cause wiping movement of said leaf spring. in the space between said blocks.

4. In an electric circuit controller having a base and a pair of fixed contacts mounted in juxtaposition on said base, a movable switch member comprising a pair of blocks of insulating m terial connected together in parallel spaced relation and mounted for pivotal movement about a transverse axis adjacent one end of one of said blocks, elongated abutments at each end of said one block extending substantially parallel to the pivotal axis of said one block and projecting toward the other of said blocks, an H-shaped leaf spring having a transverse leg, said spring being seated on said abutments with said transverse leg parallel to said abutments and intermediate the ends but adjacent the unpivoted end of said blocks, the side legs of said leaf spring extending.

beyond said unpivoted end of said blocks, elongated abutments on said other block parallel to said pivotal axis and projecting toward said one block intermediate the spaced abutments of said one block, said intermediate abutments engaging the side legs of said leaf spring and holding said spring in clamping relation between said blocks, a point abutment on said other block extending toward but normally spaced from the mid-point of said transverse 'leg of said spring, a movable contact fixedly mounted upon the extending end of each Side leg of said leaf spring for cooperation with said fixed contacts, means normally biasing said switch member to a position to maintain said contacts separated, and actuating means for moving said switch member to engage said contacts and thereafter to effect wiping fiexure of said spring into engagement with said point abutment, thereby to maintain the pressure on said fixed contacts substantially equal over the range of wiping movement of said switch member.

5. In an electric circuit controller having a base 6 and a pair of fixed contacts mounted in juxtaposition on said base, a movable switch member comprising a pair of blocks of insulating material connected together in parallel spaced relation and mounted for pivotal movement about a transverse axis adjacent one end of one of said blocks, elongated abutments at each end of said one block extending substantially parallel to the pivotal axis of said block and projecting toward the other of said blocks, an H-shaped leaf spring having a transverse leg, said spring being seated on said abutments with said transverse leg parallel to said abutments and intermediate the ends but adjacent the unpivoted ends of said blocks, the side legs of said leaf spring extending beyond said unpivoted ends of said blocks, elongated abutment means on said other block parallel to said pivotalaxis and projecting toward said one block intermediate the spaced abutments of said one block, said intermediate abutment means engaging the side legs of said leaf spring near the pivoted end of said switch member and hold ing the said spring in clamping relation between said blocks, a point abutment on said other block extending toward but normally spaced from the mid-point of said transverse leg of said spring, a movable contact fixedly mounted upon the extending end of each side leg of said leaf spring for cooperation with said fixed contacts, and means for moving said switch member between contact opening and contact closing positions, said spring being flexed by contact engagement into point contact with said point abutment thereby to flex said spring throughout its length and to efiect wiping movement of said contacts.

6. In an electric circuit controller having a base and a pair of fixed contacts mounted in juxtaposition on said base, a movable switch member comprising a first block of insulating material pivotally mounted about a transverse axis adjacent the end of said block furthest from said fixed contacts, said first block being provided at opposite ends with elongated transverse bosses substantially parallel to the pivotal axis of said block, an H-shaped flexible leaf spring having a transverse leg, said spring being fitted on said bosses with said transverse leg disposed transversely of said block and intermediate the ends but adjacent the free end thereof and its side legs extending beyond the free end of said block, a movable contact member fixedly mounted upon each extending side leg of said leaf spring, a second block of insulating material fixed to said first block in parallel spaced relation therewith and with said leaf spring disposed between said blocks, elongated transverse bosses on said second block parallel to said pivotal axis and protruding into clamping engagement with the side legs of said leaf spring at points intermediate the bosses upon said first block and near said pivotal axis, a knob-like boss on said second block adjacent the free end of said first block and protruding toward but normally spaced from the midpoint of the transverse leg of said leaf spring,

means normally biasing said switch member in 7 contact open position, and means for moving said switch member against, its bias thereby to bring said contacts into engagement and thereafter to effect wiping movement 1 of said contacts, said leaf spring engaging said knob-like boss during said wiping movement, thereby to fiex said spring throughout its length and to maintain substantially equal pressure on the cooperating pairs of fixed and movable contacts through the range of wiping movement.

7. In an electric circuit controller having a base and a pair of fixed contacts mounted in juxtaposition on said base, a movable switch. member comprising a pair of blocks of insulat-. ing material connected together in parallel spaced relation and mounted for pivotal movement about a traverse axis adjacent one end of one of said blocks, said one block being provided at opposite ends thereof with spaced apart elongated abutments extending parallel to the pivotal axis of said block and projecting toward the other said block, said other block being provided with an elongated abutment parallel to said pivotal axis and projecting toward said first block intermediate the abutments on said first block, an elongated flexible leaf spring held in clamping relation between said elongated abutments and having a bifurcated portion extending beyond the ends of said blocks nearest said fixed contacts, a point abutment on said other block approximately at its end nearest said fixed contacts and extending toward but normally spaced from said spring, a movable contact fixedly mounted upon each 8 furcation of the extending end of said spring for cooperation respectively with one of said fixed contacts, means for moving said switch member between contact opening and contact closing positions, said leaf spring engaging said point abutment on said second block when said contact is closed, thereby to fiex said leaf spring throughout substantially its entire length in said contact closing position to effect wiping movement of said contacts.

EDUARD T. GRANT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Guler Feb. 17, 1942 Seeley Mar. 10, 1942 Ebert Aug. 29, 1944 McMaster et a1 Aug. 6, 1946 Number Certificate of Correction Patent No. 2,501,507 March 21, 1950 EDUARD T. GRANT It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 27, for the Word molding read holding;

and that the said Letters Patent should be read With this correction therein that the same may conform to the record of the case in the Patent Office. Signed and sealed this 29th day of August, A. D. 1950.

[SEAL] THOMAS F. MURPHY,

Assistant Oommissz'oner of Patents.

Certificate of Correction Patent No. 2,501,507 March 21, 1950 EDUARD T. GRANT It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 27, for the Word molding read holding;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 29th day of August, A. D. 1950.

[an] I THOMAS F. MURPHY,

Assistant Uommzssz'oner of Patents.

Certificate of Correction 7 Patent No. 2,501,507 March 21, 19 50 EDUARD T. GRANT It is hereby certified that error appearsin the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 27, for the Word molding read holding;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 29th day of August, A. D. 1950.

[snarl] THOMAS F. MURPHY,

Assistant Gammz'ssz'oner of Patents. 

